Effect of voluntary intake of iodinated salt on prevalence of goitre in children.

The availability of iodinated salt containing 20 mg of iodine as iodate/kg salt consumed on a voluntary basis enabled us to investigate its effect on goitre prevalence and iodine excretion in urine in a longitudinal, prospective, randomized study over 4 years. With this salt, under the assumption of a consumption of 5 g salt per day and person, an additional intake of 100 micrograms of iodine can be achieved. The study was performed on initially 334 children (168 boys, 166 girls) at the age of 10 years living in an area of iodine deficiency. After 4 years, 286 children still participated in the study. Initially, goitre prevalence as assessed by palpation was found to be 30.5% (37.4% in girls and 23.8% in boys). Neck circumference was found to be significantly higher in children with goitre compared with those without (30.2 +/- 1.4 vs 29.4 +/- 1.4 cm; P less than 0.001). Iodine excretion in the urine was significantly lower in children with goitre compared with those without (40.4 +/- 16.7 micrograms/g creatinine vs 46.1 +/- 24.9 micrograms/g creatinine; x +/- SD; P less than 0.05). The children were randomly assigned to two different groups: group A (N = 146) was asked to use iodinated salt, group B (N = 188) non-iodinated salt. Over the 4 years, a continuous increase in iodine excretion in urine could be demonstrated in group A.(ABSTRACT TRUNCATED AT 250 WORDS)